MBE 4000 DDEC VI Troubleshooting – Section 42.2 SPN 558/FMI 3

Section 42.2
SPN 558/FMI 3

This diagnostic condition is typically an open circuit.‪

Section 42.2.1
Open Circuit Check

Check for open as follows:‪

1. Disconnect the Idle Validation Switch.
2. Turn the ignition ON (key ON, engine OFF).
3. Measure the voltage between the Idle Validation Switch pins 4 and 6.
   1. If the voltage is greater than 11.5 volts, go to step 7 .
   2. If the voltage is less than 11.5 volts, go to step 4 .
4. Measure the voltage between the Idle Validation Switch pin 4 and ground.
   1. If the voltage is greater than 11.5 volts, go to step 5 .
   2. If the voltage is less than 11.5 volts, repair the open wire between pin 6 of the CPC #1 connector and pin 4 of the Idle Validation Switch. Refer to "42.2.1.1 Verify Repairs" .
5. Disconnect the CPC #2 connector.
6. Measure the resistance between pin 2 of the CPC #2 connector and pin 6 of the Idle Validation Switch.
   1. If the resistance is greater than 5Ω, repair the open the wire between pin 2 of the CPC #2 connector and pin 6 of the Idle Validation Switch. Refer to "42.2.1.1 Verify Repairs" .
   2. If the resistance is less than 5Ω, replace the Idle Validation Switch. Refer to "42.2.1.1 Verify Repairs" .
7. Measure the voltage between the Idle Validation Switch pins 5 and 6.
   1. If the voltage is greater than 11.5 volts, replace the Idle Validation Switch. Refer to "42.2.1.1 Verify Repairs" .
   2. If the voltage is less than 11.5 volts, repair the open the wire between pin 3 of the CPC #1 connector and pin 5 of the Idle Validation Switch. Refer to "42.2.1.1 Verify Repairs" .

Section 42.2.1.1
Verify Repairs

Verify repairs as follows:‪

1. Turn ignition OFF.
2. Reconnect any electrical connections that were disconnected to perform the diagnosis.
3. Clear codes with DDDL 7.0 or latest version.
4. Start and bring engine up to operating temperature (over 140°F/60°C).
5. Verify operation is satisfactory and no warning lamps illuminate. If warning lamps illuminate, troubleshoot the codes. If assistance is required, call the Detroit Diesel Customer Support Center at 313–592–5800.